Answer:
Speed of the plane over the ground is 429.33 km/hr due West and 70 km/hr towards North
Solution:
According to the question:
Wind flowing in South direction,
![v_(s) = 70.0 km/h](https://img.qammunity.org/2020/formulas/physics/college/caflqnqf7rn8h1ailpswiu5iatcbi2yaeo.png)
Air speed,
Now,
The velocity vector is required 70 km/h towards north in order to cancel the wind speed towards south.
Therefore,
The ground speed of the plane is given w.r.t fig 1:
![v_(pg) = \sqrt{v_(a^(2)) - v_(s)^(2)}](https://img.qammunity.org/2020/formulas/physics/college/fjwmy5uqocpgf4gfvmbx8bnzkr6318kun4.png)
![v_(pg) = \sqrt{435.0^(2) - 70.0^(2)} = 429.33 km/h](https://img.qammunity.org/2020/formulas/physics/college/xvh8jkeuwcjyjsi6cxnxr43n6568xmu5kr.png)